Yes, and apparently not, and yes. There are plenty of games that support HDR. Destiny 2 is free to play and supports HDR, and ROTR looks great in HDR.
The problem for implementing this requires cooporation in so many parties it’s not even funny. The viewing of HDR images needs to work on Android and iOS to actually get the ball rolling. What’s the point in making HDR images (which ATM you can’t even do that) if nobody can see them because the SW doesn’t support it?